Also, that Assassin in A3, Natalya or w/e. She basically helped you in no way.

She gave you tips, but you never needed tips to beat the game. It's game immersion, much like the galaxy map in StarCraft 2. Useless people/features to get you inside the universe. Technically, her existence helped you more in terms of making the game live in our minds longer. Gameplay wise, she did nothing. Except show you a teaser of an upcoming character, obviously the assassin.

Natalya was removed from Act III after you beat Mephisto, but there was a small window of opportunity where you COULD access her post-Act III dialogue which pretty much tells you about Lord of Destruction.

For some reason I always liked listening to their dialog, except for Cain who would babble about something for 10 min when he could have summarized into a much, much shorter speech. Ormus is still the best.